Does Zero Dark Thirty glorify torture? I cannot tell you. I haven’t seen it yet. Nor—at least as of his writing of his column Monday—had Glenn Greenwald. But Greenwald, writing in the Guardian, became a prominent voice attacking Kathryn Bigelow’s movie for an extended sequence of torture that—some people who have seen the movie say—the film implies helped the U.S. find and kill Osama Bin Laden. (Not everyone who’s seen the movie agrees with this interpretation.) Greenwald, who has written passionately for years about civil liberties and the war on terror, says the movie “propagandizes the public to favorably view clear war crimes by the US government, based on pure falsehoods.”

Not wanting to make one more sweeping judgment of a movie on the basis of a few other people’s viewing, I’m going to leave the glorifying-torture question there. But I can talk about Greenwald’s larger argument, which says a lot about how different kind of people view art, how they judge it and what they think its purpose is.

Namely: is it possible that a movie, a book or any other creative work can be deceptive, misleading, propagandistic, even immoral, yet still be great?

“This, of course, is a long-standing debate about film specifically and art generally,” Greenwald notes in his column. But it’s a debate that seems to be resolved pretty plainly in his mind: no, it can’t. A good chunk of his critique is not just aimed at Zero Dark Thirty and secondhand reports of its content. It’s also about the critics who have given it rave reviews, even when, like David Edelstein of New York magazine, they criticized its depiction of torture (“borderline fascistic… an unholy masterwork“). Greenwald objects, as much as anything, to “the reaction to the film: the way in which its fabrications about the benefits of torture seem to be no impediment to its being adored and celebrated.”

Is it really so difficult to accept that one failing of an artwork—if Greenwald’s description is in fact correct—does not disqualify it for being praised for its triumphs? “The fact that [director Kathryn Bigelow is] presenting lies as fact on an issue as vital as these war crimes, all while patting herself on the back for her ‘journalistic approach’ to the topic, makes the behavior indefensible, even reprehensible,” Greenwald writes. “Is it really possible to say: this is a great film despite the fact that it glorifies torture using patent falsehoods?”

Apparently not, in Greenwald’s view. It is so impossible, in fact, that he must come up with an alternative explanation for the positive reviews: “I don’t believe that this film is being so well-received despite its glorification of American torture. It’s more accurate to say it’s so admired because of this.”

In other words—in what is sadly now the standard form of political and other argument—he accuses his targets of bad faith. The reason reviewers give for praising the movie is false, and Greenwald knows the right one. A critic who says that Zero Dark Thirty is great despite its depiction of torture is either lying or does not know his or her own mind.

Rather, Greenwald says, critics, like post-9/11 Americans generally, want to be told positive stories about the war on terror. Thus, “Any film that powerfully and adeptly leads Americans to view their government and its intelligence and military actors as noble heroes is one that is going to produce gratitude and glee no matter what else it does.”

Because why else could anyone say positive things about a movie that might please Dick Cheney? How could anyone acknowledge artistic merit in a work that undermines The Cause? Cognitive dissonance resolved!

It’s a simplistic way of looking at art, but it’s not surprising, because Greenwald is a political writer (or at least an ideological public-affairs writer), and this is the political way of looking at art. For someone who’s passionate about policy and public issues, aesthetics are secondary. Utility comes first. Things help the cause or they hurt it. There are Parts of the Solution and there are Parts of the Problem.

There are several bad assumptions that go into that kind of thinking. For one, that the primary function of art is to serve, or at least not undermine, one’s desired political arguments. For another, that artworks have literal, direct and easily predictable effects. In this kind of worldview, one kind of entertainment makes people more conservative, another makes them more liberal.

To this mindset, things like beauty and emotional force do matter, because they move us–but, more important, because they’re the spoonful of sugar in which good and righteous artists encase the medicine-pill of right-thinking. Entertainments and art can thus be judged by whether or not they push people in the right direction. (Further, any reasonable intelligent person knows this to be true; hence the need to create a bad-faith explanation for critics who love ZD30 despite its flaws.) To think otherwise is to enable evil: hence, Greenwald invokes Godwin’s Law, bringing up the artistic defenses of Hitler’s filmmaker Leni Riefenstahl.

If this way of seeing art were accurate, politicians would make great artists and artists would be our finest political pundits. But it’s not. Film history is full of movies that are false, amoral, brutal, sadistic—take the films of Sam Peckinpah or Quentin Tarantino—yet are triumphs of vision and storytelling. The idea of the great film that embeds false, even wicked ideas goes at least back to D.W. Griffith’s KKK-glorifying “The Birth of a Nation,” which propagandized horrific racism and revolutionized what directors could convey with movement on a screen. And on that, I’ll turn the discussion over to Roger Ebert, who also knows a thing or two about politics, in his fantastically well-reasoned essay on that film:

Like Riefenstahl’s “The Triumph of the Will,” it is a great film that argues for evil. To understand how it does so is to learn a great deal about film, and even something about evil.

But it is possible to separate the content from the craft? Garry Wills observes that Griffith’s film “raises the same questions that Leni Riefenstahl’s films do, or Ezra Pound’s poems. If art should serve beauty and truth, how can great art be in the thrall of hateful ideologies?”

The crucial assumption here is that art should serve beauty and truth. I would like to think it should, but there is art that serves neither, and yet provides an insight into human nature, helping us understand good and evil.

Art engages good and evil and leaves its audience to continue the argument when the story is over. And this is where ideologues get uncomfortable with art. Because art also leaves the troubling possibility that the audience might choose wrong. That they might draw the wrong conclusions, that—misled by dramatic license or swept away by raw emotion—they could be led to wrong thinking. People might be amused by how Tom Sawyer treats Jim in Huckleberry Finn. TV fans might get a secret kick out of all the things that Archie Bunker says. This is not what political argument does: political argument makes sure it always has a hand on your wrist to lead you to the desired end.

Try to make art that does that, and you generally end up with Atlas Shrugged. But as we already know, there are plenty of politicians that love themselves some Atlas Shrugged.

And that’s why, as Greenwald’s argument with critics exemplifies, political true believers have a hard time trusting aesthetes. They leave room for interpretation and wrong choices. (Some viewers who’ve previewed Zero Dark Thirty believe it argues that torture helped get Bin Laden; others who have seen it don’t think the film argues that at all. Which suggests that maybe the movie does what art often does: avoids giving the audience clear, highlighted answers.) They cannot be trusted to place the correct agenda over all else. They choose foo-foo sophistry about “nuance” and “insight” and “metaphor” over literal truth and the clear, correct argument. Their loyalty, in the end, is suspect.

None of which is to say that partisans and political sorts hate art or that they’re Philistines. (For all I know Glenn Greenwald loves the movies.) But it is why alliances between art and ideology tend to go badly in the end. Art does a lot of powerful, wonderful things. But one thing it’s really bad at is taking orders.